Abstract The following characteristics of the effector cells for natural cytotoxicity (NC) against BALB/c Meth A tumor cells in BALB/c and other mouse strains were observed: 1) time course studies showed that most of NC was completed by 12 to 24 hr of incubation; 2) pre-incubation at 37°C for as long as 6 days had no effect on NC activity; 3) pre-treatment with ammonium chloride had no effect on NC activity; 4) NC cells were not adherent to plastic surfaces; 5) NC cells showed some degree of adherence to nylon wool fibers and activity was recovered from the adherent population; 6) NC cells were partially retained by G10-Sephadex columns; 7) by using velocity sedimentation at unit gravity in Ficoll gradients, NC cells were homogeneous having an average sedimentation velocity of 4.3 to 4.5 mm/hr; 8) treatment with carbonyl iron and magnetism had no effect on NC activity; 9) treatment with various antisera + C including, anti-Thy 1, anti-Lyt 1, anti-Lyt 2, anti-Ala 1, anti-NK, rabbit anti-mouse brain, and rabbit anti-mouse Ig, had no effect on NC activity; 10) heat-aggregated Ig had no effect on NC-mediated CMC; 11) trypsin treatment decreased NC activity but the effect was reversible, dependent on trypsin dose, and detected only in short-term CMC assay. These properties were similar for NC cells obtained from normal or nude mice, as well as peritoneal exudates obtained 5 days after i.p. BCG. When compared to the properties of the NK cell, many similarities were evident although differences in sensitivity to pre-incubation at 37°C and in the relative degree of adherence to nylon fibers were found. It is proposed that both the NC and NK cells belong to a family of effector cells with similar functions.
The following characteristics of the effector cells for natural cytotoxicity (NC) against BALB/c Meth A tumor cells in BALB/c and other mouse strains were observed: 1) time course studies showed that most of NC was completed by 12 to 24 hr of incubation; 2) pre-incubation at 37°C for as long as 6 days had no effect on NC activity; 3) pre-treatment with ammonium chloride had no effect on NC activity; 4) NC cells were not adherent to plastic surfaces; 5) NC cells showed some degree of adherence to nylon wool fibers and activity was recovered from the adherent population; 6) NC cells were partially retained by G10-Sephadex columns; 7) by using velocity sedimentation at unit gravity in Ficoll gradients, NC cells were homogeneous having an average sedimentation velocity of 4.3 to 4.5 mm/hr; 8) treatment with carbonyl iron and magnetism had no effect on NC activity; 9) treatment with various antisera + C including, anti-Thy 1, anti-Lyt 1, anti-Lyt 2, anti-Ala 1, anti-NK, rabbit anti-mouse brain, and rabbit anti-mouse Ig, had no effect on NC activity; 10) heat-aggregated Ig had no effect on NC-mediated CMC; 11) trypsin treatment decreased NC activity but the effect was reversible, dependent on trypsin dose, and detected only in short-term CMC assay. These properties were similar for NC cells obtained from normal or nude mice, as well as peritoneal exudates obtained 5 days after i.p. BCG. When compared to the properties of the NK cell, many similarities were evident although differences in sensitivity to pre-incubation at 37°C and in the relative degree of adherence to nylon fibers were found. It is proposed that both the NC and NK cells belong to a family of effector cells with similar functions.
Abstract Natural cell‐mediated cytotoxicity (NCMC) against a variety of tumor targets is mediated by a heterogeneous group of effector cells with the natural killer (NK) and natural cytotoxic (NC) cells being the predominant prototypes in mice. This report shows that non‐lymphoid tumor targets, mostly derived from chemically induced fibrosarcomas, are susceptible to either (I) NK‐mediated lysis with all the activity being the function of a poly‐IC augmentable Qa‐5+ effector cell; (2) NC‐mediated lysis with all activity being the function of a Qa‐5—cell not augmented by poly‐IC; and (3) a combination of NK‐and NC‐mediated lysis with activity being the function of both Qa‐5+ and Qa‐5‐ cells, the NK (Qa‐5+) augmented by poly‐IC. These studies further support the view that murine NC and NK cells are distinct and collectively make up the NCMC system, and also that the previous association of NK cells with lymphoid tumor lysis and NC cells with nonlymphoid tumor lysis is not a valid one.
